Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

1UIUCUH

Longer-Term Coupling AnalysisPieces

Develop Understanding of Complex Coupling

Incorporate into Topological Models

Validate Simpler Topological Models

(Twelve to Twenty-Four Months)

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

2UIUCUH

Long-Term ProblemsNested Boxes with Slots and Wires

• Develop understanding of complex coupling

• Boxes with wires and slots

• Nested boxes with wires and slots

• Coupled boxes with wires and apertures

• Embed pieces in topological structures

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

3UIUCUH

Wire thru Hole in Box with Interior Feature

Wire

Small HoleMetal Box

Interior Feature

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

4UIUCUH

Nested Boxes with Wire thru Holes

Wire

Small HoleMetal Box

Interior Feature

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

5UIUCUH

Alternate Wire Route & Slotted Box

Wire

Small HoleMetal Box

Interior Feature

Slot

Wire

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

6UIUCUH

Multiple Boxes in Box with Wire

Wire

Small HoleMetal Box

Interior Features

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

7UIUCUH

Multiple Boxes, Slotted Boxes, Wire through Walls

Wire

Small HolesMetal Box

Interior Features

Slots

Wire

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

8UIUCUH

Rectangular Cavity Coupled to Coaxial Cavity via Wire in Hole

Wire

Small HoleMetal Box

Interior Feature

Slot Coaxial Cavity

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

9UIUCUH

Coupled Cavities Rectangular-Coaxial-Rectangular

W ire

Sm all H oleM etal Box

S lot

Interior Features

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

10UIUCUH

Long-Term ProblemsCovered (Shielded) Apertures

• Develop understanding of shielded apertures

• Slot in screen covered by “grounded” shield

• Slot in upper plate of parallel plate guide covered by covered by “grounded” shield

• Embed in topological structure

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

11UIUCUH

Shielded Slot in Screen

A

BC

A

BC

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

12UIUCUH

Shielded Slot in Plate of Guide

R egion a

R egion c R egion o

R egion bA

BC

R egion a

R egion c R egion o

R egion bA

BC

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

13UIUCUH

Long-Term ProblemsFast Time-Domain Methods

Development

• Fast time-domain integral equation methods for inhomogeneous material regions

• Accurate TDIE for weak penetration through apertures

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

14UIUCUH

Proposed Effort (Year 1): Algorithms and Implementations

• Develop “low frequency” stable PWTD / TDIE solver (12 mo)– Hybridize loop/star/tree and time Galerkin

schemes (Industry strength implementation)

• Develop stable/accurate TDIE solvers for cavities with very small holes / seams / cracks (18 mo).

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

15UIUCUH

Proposed Effort (Year 1): Demonstration of Capabilities

• Analyze coupling into a nonlinear circuit (amplifier) in a realistic enclosure (12 mo)– Geometry: Slots, cavities, pins,

nonlinear circuitry.

– Demonstrates all capabilities of solver

– Validation: through comparison to FDTD solution.

slotcircuitry

cavityboards + pins

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

16UIUCUH

Long-Term ProblemsFast Frequency-Domain Methods

Development• Fast frequency-domain integral equation methods for

exterior-to-interior coupling problem• Fast frequency-domain integral equation methods for

very low frequencies (for FFT)• Fast hybrid methods• Accurate fast frequency-domain integral equation

methods for weak penetration through apertures

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

17UIUCUH

EMI Threat to Aircraft SystemsAirborne Transmitter

Ground-based orship-board Transmitter

PEDSLightening

External Threat

• Coupling from other Aircraft Systems• Natural Environmental Effects (Lightening, Static Electricity)• Man Made Sources External to the aircraft (High Intensity Radiated Fields - HIRF)

Internal Threat

• Portable Electronic Devices (PEDS) carried by passengers

Picture from NASA-Langley

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

18UIUCUH

Penetration through Loaded Slots with Wire Bundles

• Adapt hybrid frequency domain methods for coupling characterization in presence of wire bundles through loaded geometries

• Develop an understanding of good shielding practices and relative levels of penetration among the various slots geometries

• Develop methods for equivalent circuit extraction

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

19UIUCUH

Coupling through Antennas

• Antennas are ‘doors’ to coupling from external excitations into structures

• For coupling studies, details such as wires, feed structures and loading are crucial

• Provide an understanding of coupling (in-band and out of band)

Patch or array

Vout

feed

e

r1

e

r2

e

r3

e

r4

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

20UIUCUH

Coupling though Slots in Loaded Structure

• Develop general purpose frequency domain techniques for coupling into loaded geometries

• Develop hybrid methods appropriate to structure and material: finite element method, integral equations with multilayer Green’s functions, and fast multipole integral methods

• Validate and compare

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

21UIUCUH

Long-Term ProblemsApplication of EIGER

• Analysis of complex coupling problems

• Use as a check on more problem-specific analyses

• Coupling to PC board traces, for example

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

22UIUCUH

Aperture Coupling to PCB Traces

• Analysis should include mutual coupling effects between traces.

• Requires efficient layered-media periodic Green’s function (Ewald acceleration, etc.).

IC

E inc

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

23UIUCUH

Cable Coupling to PCB Traces

• Analysis should account for cable propagation to traces.

• Analysis should also account for aperture/cable radiation effects.

IC

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

24UIUCUH

Coupling to PCB Traces

• Thevenin equivalent circuits can be obtained to model both aperture and cable penetration.

• Thevenin equivalent circuits model all EM effects up to the IC pin.

• This allows for convenient de-coupling between EM analysis and IC analysis.

IC +

-

ZT

VT